Yes — at least in part. That's the belief of neuropsychologist Steve Suomi of the National Institutes of Health (NIH), who is studying the personalities of monkeys, and it's also the belief of every one of the dozen or more scientists we interviewed.

We all enter the world with a propensity for more or less confidence, and the case goes well beyond the serotonin transporter gene we share with rhesus monkeys.

"A lot of personality is biologically driven," says Dr. Jay Lombard, one of the founders of Genomind, a pioneering genetic testing company. "It is clearly both nature and nurture, and understanding what genes do to affect the biology of the brain, to create temperament, is something the NIH has now recognized as a priority."

In terms of scale and duration, one of the most compelling studies that links genes and confidence is a project being conducted by Robert Plomin, a renowned behavioral geneticist at King's College in London. While he can't quite replicate the perfectly sealed and studied Suomi-like habitat, he comes close. And he's doing it with humans.

Twenty years ago, Plomin decided to undertake an ambitious study of 15,000 sets of twins in Britain. He's followed them from birth into adulthood, gaining vast amounts of data on everything from intelligence to a propensity for disease to gender roles. Some of those twins are identical with identical DNA; others are fraternal and share only similar DNA in the way that ordinary siblings do. Twins have long been the most effective subjects for the study of the nature versus nurture conundrum.

In his recent examination of the academic performance of these twins, Plomin decided to take a closer look at confidence, or the faith the children had in their ability to do well. The twins had been given a standard IQ test at age seven, then again at age nine, and they were tested academically in three subjects: math, writing, and science. Next, they were asked to rate how confident they were about their abilities in each subject. Plomin and his researchers also factored in reports from the teachers.

Once all of the data had been cross-referenced, the research team was struck by two findings. The students' self-perceived ability rating, or SPA, was a significant predictor of achievement, even more important than IQ. Put simply, confidence trumps IQ in predicting success.

The researchers also found that a lot of confidence comes in our genes. They'd separated the confidence scores of the identical twins from those of the fraternal twins, and found the scores of the identical twins to be more similar. Plomin's findings suggest that the correlation between genes and confidence may be as high as 50%, and may be even more closely correlated than the link between genes and IQ.

That a personality trait as seemingly amorphous as confidence might be every bit as inheritable as intelligence struck us as pretty far-fetched; until we discovered we'd ventured upon an entire field of study, the genetics of personality, at a remarkably explosive stage. Countless breakthroughs in the field of behavioral genetics and biology over the past decade have created ever more sophisticated ways to examine the mind in action as well as cheaper, more efficient methods to sequence and compare DNA.

Hundreds of these studies — involving genes, brain fluid, behavior, and neuroimaging — make a strong case that large chunks of our personality are formed at conception. Researchers have pinpointed genes that influence everything from shyness to motivation to criminal behavior to a proclivity to be a professional dancer.

It should be noted that some of the experts we talked with don't agree with Plomin's conclusion that confidence is half genetic. They say that broader personality traits — the big five, as they have become known — are accepted to be about 50% genetic. Those are openness, conscientiousness, extraversion, agreeableness, and neuroticism. But they would put attributes such as optimism and confidence, which are considered facets of the big five, in the range of 25% inherited.

We were still surprised. Whether we get 50% of our confidence in our genes, or 25%, it's a big chunk, more than we would have thought. It won't be long, we figured, before newly pregnant women will be able to take a quick fetal DNA test to determine whether they should invest in safety locks and padded walls or cuddly toys and books.

As tantalizing and voluminous as the science is at this point, it's hardly exact. It turns out that sifting through our 20,000 genes is slow going. Nothing resembling a complete or partial genetic personality code yet exists. Remember, in the 20 or so years since genetic research has taken off, the emphasis has been on pathology — physical and mental illnesses — rather than on the genetic building blocks of health and wellbeing. That's just starting to change.

Now, the equally interesting question is becoming: What do the genes of psychologically strong, healthy people look like?

Not surprisingly, intelligence is the positive attribute that has received the most attention. Researchers around the world have already uncovered at least one intelligence gene by comparing DNA and IQ scores. A young Chinese researcher, Zhao Bowen, is looking for another one, his sequencing machine is on overdrive, going through DNA samples from the world's smartest people.

Nobody has undertaken a project yet to extract DNA samples from the world's most confident people, and none of the scientists we spoke to believe that there will be just one so-called confidence gene. As is the case with many complex personality traits, scientists told us that confidence is influenced by a large number of genes, dozens or more, which creates a messy stew of hormones and neural activity.

Confidence involves both emotion and cognition. Indeed it has a metacognitive component, because it involves our knowledge about our brain at work. In other words, it's not simply about whether we can do a task, but whether we assess ourselves to be capable of doing that task.

Even so, scientists are drilling all around the perimeter of confidence these days, as they examine related personality attributes, such as optimism and anxiety. Their work makes it possible to piece together an early, basic formula.

How confident are you? Take the quiz, the first of it’s kind to broadly measure confidence in women, here. You’ll not only learn how you stack up, and what you can do about it, but you’ll also be contributing to a cutting edge research project.